Punching bag



J. C. CHUPA PUNCHING BAG A ril 6, 1965 Filed NOV. 12, 1959 IN VEN TOR.

JOH C CHUPA FIG. 3

A TTORNEYS 'ice 3,176,985 PUNCHING BAG John C. Chupa, Sandusky, Ohio, assignor to The Barr Rubber Products Company, Sandusky, Ohio, 21 corporation of Qhio Filed Nov. 12, 1959, Ser. No. 852,454 8 Claims. (Cl. 27277) The present invention relates to a punching bag, and, more particularly, to an inflatable punching bag comprising a cast vinyl plastic in which means are provided for mitigating the stresses occurring in the bag.

Heretofore, punching bags have customarily consisted of a rubber or leather casing having a bladder and an opening through which the bladder is inserted, the opening being closed by lacing or the like. Normally, the bags are secured to a swivel hook by buckles or similar means sewed to the necks of the bags. The primary disadvantage of this construction is that the buckles frequently tear loose since when a punching bag is struck a blow the stress is concentrated at the point where the buckle connects to the bag. The durability of a conventional punching bag is further limited by its construction in which the lacing often breaks and in which the bladder is subjected to being ruptured.

Other disadvantages of conventional bags are their relatively high cost of manufacture and their limited versatility in that the bags must be hung below the connecting swivel.

The present invention provides a rugged and durable punching bag which includes a stress-mitigating insert in the neck of the bag connected to a swivel or other appropriate support. The bag has an unusually long service life and is inexpensive to manufacture because of its cast, one-piece construction in which lacing and bladder are eliminated. Additionally, the invention is versatile in its use since it may be used in an upright position in which it is connected to a flexible rod, as well as being hung from a swivel-type hook in the customary manner.

Other objects and attendant advantages of the invention will become readily apparent as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:

FIGURE 1 is an isometric view of the invention partially enclosed in a mold.

FIGURE 2 is a' cross-sectional view of the invention enclosed in a mold taken along the line 22 of FIG. 1 looking in the direction of the arrows.

FIGURE 3 is an enlarged, cross-sectional view of a fragmentary portion of the invention taken along the line 3-3 of FIG. 2 looking in the direction of the arrows.

Referring now to F168. 1 and 2, there is shown a pearshaped punching bag 1% enclosed in mold sections 23 and 24. The bag has a valve 15 molded in the casing 11 at the large end, and has a composite insert 16 suitably fused or molded in the neck. The valve 15 is leakproof under shock of severe impact, and may conveniently be of the type described in the copending application of John C. Chupa, Serial No. 429,162, now Patent No. 2,934,344, filed May 12, 1954.

According to the invention, the bag 16 is of a cast, one-piece construction and consists essentially of a resin and a non-volatile plasticizer therefor. Because of the cast construction, the stress-mitigating insert 16, through which the bag is secured to a support, can be permanently bonded to the bag in a manner which prevents the neck of the bag from tearing and from breaking loose from the support when strucka severe blow.

The insert 16 consists of body 17 formed from a compound similar to that of the bag wall 11, although somewhat stiffer and less flexible, which is either molded or extruded around a rigid, threaded adapter element 18. The adapter means may be made from metal or other suitable material, and has a flange 19 which prevents it from tearing away from the outer end of body 17. The inner end of the insert 16 has a bell-shaped cavity 21 which substantially conforms in contour to a stress diagram of the stresses occurring in the neck when the bag is struck a blow and, the insert distorted from an axial plane. By virtue of the insert 16 and the shape of cavity 21, stresses which tend to rupture the necks of conventional bags and to tear them from their support are gradually mitigated by the tapered wall section 22 surrounding the cavity. As a result, the normally' severe stress at the point where the bag is connected to a support are substantially eliminated. The insert further provides a stifi support within the neck thus preventing the neck of the bag from collapsing.

When used, the punching bag may be hung from a swivel-type hook which has an end threaded into the adapter means 18. Alternatively, the bag may be supported in an upright position by a flexible rod connected to the adapter. In either case, the life of the bag is greatly enhanced by having the adapter embedded in the neck instead of having a buckle sewn to the exterior of the bag where it can easily be torn ofi as is presently the case in most punching bag construction.

An exemplary formulation for a plastisol of which the bag 10 may be formed is set forth below:

Parts by weight High molecular weight polyvinylchloride in the form of a fine white powder, specific gravity ap- The above formulation may be molded into the desired shape by means of the mold shown in FIGS. 1 and 2. Mold sections 23 and 24 have external bosses 25 and 26 and are formed with complementary cavities conforming to the shape of the punching bag. The portions of the mold sections which form the neck of the bag are recessed to seat a core support 27. The support 27 is threaded into adapter 18 and serves to position the preformed insert 16 out of contact with the mold walls whereby the casing of the bag may be formed around and permanently bonded to the insert. The opposite end of mold section 23 has an aperture which receives a core pin 28 designed to position the valve during casting.

With the valve and insert properly positioned, a suitable amount of the vinyl compound is injected into mold section 24 at which time the mold is closed and rotated about a plurality of axes by an apparatus such as disclosed in the copending application of John C. Chop a, Serial No. 456,573, now Patent No. 2,934,344, filed September 16, 1954. Heat is then applied to the rotating mold to jell and fuse the vinyl compound. Subsequently, the mold is cooled and the finished article removed.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be under-stood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1.' A punching'bag comprising a hollow casing having a neck and a stress-mitigating insert having an inner end and an outer end in said neck, the inner end of said insert Patented Apr. 6, 1965 having a bell-shaped cavity, said cavity substantially conforming incontour to a stress-diagram of the stresses occurring the neck.

2. A punching bag as claimed in claim 1 in which said insert has", an adapter means embedded in said outer end, said adapter means being'adapted to be connected to asupport for, said-bag. s

33A punching-bag comprising a one-piece hollow casing having a neck, said casing consisting essentially of a fusedresin and non-volatile 'plasticizer, a leakproof air ture the neck of said casing at the juncture with saidvalve bonded to the innersside of said casing, and asstress mitigating insert permanentlysecured in said neck, said insert having an outer end in which is embedded an adapter means and an inner end in which there is a hellshaped 'cavity, said 'cavity substantially conforming 'in contour to a stress-diagram of the stresses occurring in said neck. H i g i 4. A punching bag as claimed in claim 3 in" which said insert'consists of a compound similar to that, of

c said casing. j

5. A stress-mitigating insert for use in punching bags and the likehaving a bell-shaped cavity in one end,

-said cavity substantially conforming in contour to 5 a stress-diagram of the stresses occurring in said insert whe the insert is distorted from an axial plane. 7

6. A stress-mitigating insert as claimed in claim 5 in which said insert consists essentially of a fused resin and a non-volatile plasticizer, and in which a rigid adapter means is embedded in the; other end of said insert..

7; A punching bag comprising ahollow, generally-pearshaped casing having a neck recess and a stress-mitigatinsert.

8. A punching bag as claimed in claim 7 wherein said insert is completely enclosed Withinfsaid neck, said bag includes means embedded within said insert for securing said bag to a support, and said taperedwall section extends inwardlycwithin the casing from the location of said embedded support securingmeans. V

1 References Cited by me Examiner I UNITED STATES PATENTS 758,279 4/04 Rhodes 272-77 923,379 j 6 09 Selfe 272-77 1,158,009 19/15 Stephen. f 2,549,197 4 51 ,Hayes 273 5s 2,653,817 9/53 Tebbetts' 273 5s 2,740,630 4/56 Robinson 272 77 2,894,746 7/59 Chupa ;272 ;7s- 2,941,805 6/60 LOUIS R. PRINCE, Primary Examiner.

ELLIS E. FULLE 'LEONARD w. VARNER, JR.,

' DELBERT B. LOWE, Examiners.

and substantially filling the Chupa 273 58 

1. A PUNCHING BAG COMPRISING A HOLLOW CASING HAVING A NECK AND A STRESS-MITIGATING INSERT HAVING AN INNER END AND AN OUTER END IN SAID NECK, THE INNER END OF SAID INSERT HAVING A BELL-SHAPED CAVITY, SAID CAVITY SUBSTANTIALLY CONFORMING IN CONTOUR TO A STRESS-DIAGRAM OF THE STRESSES OCCURRING IN THE NECK. 